Victor is an assassin for the CIA.
He becomes connected to the Agency in the second book while in the first he is a freelance killer, one with many, many years of experience at his trade. He likes his freedom and his anonymity but often you cannot get what you want and Victor has learned to survive above all else. He has had to because he works alone and usually in considerable secrecy. He seems at times to prefer it though other times he does think how it would be to live a 'normal' life. Do not expect a great deal of angst in that regard, however. He does not spend any appreciable amount of time bemoaning his situation. Being a survivor, he makes do and goes on living.
The same cannot be said for his targets. Victor is extremely capable when it comes to killing and he rarely misses and never a second time. He is methodical and extremely careful, going to great lengths to have escape routes clearly defined before stepping into the fray.
Victor does not have a last name, at least one we are told. He has a near-endless supply of aliases, all bought and paid for, so he can change identity quickly and easily and does so frequently. He does not have the same face all the time having spent more than one session with plastic surgeons. At one point he wondered if he could even remember what he once looked like.
And he does not have, or so we come to realize, a nationality. He is white and that is about the most that can be said. His knowledge of languages and dialects and accents is superb as is his ability to switch between them easily. To some he is French, to others German or Slavic, and to others he is English. Some consider him American. The readers do not get any more clues than the characters he encounters.
In the opening book he is working to the CIA but not knowingly, even by the Agency [you need to read it to understand]. In the second book he is definitely under the control of a major official inside Central Intelligence but it is an off-the-books operation and not officially sanctioned. They refer to him with the name Tesseract but it is more of a codename than anything else and when he learns of the epithet, he is less than pleased. He is also not thrilled with having to work with such a public organization because secrecy has been his best defense. Nevertheless, he knows that bucking the CIA and their thousands of employees and billions of dollars would not be a wise move.